Immune system loses power with long-term air pollution exposure

Researchers have identified a slow-burn impact of air pollution, which increases pressure on a range of healthcare departments.

Immunologists at one of the US’ leading academic institutions have published a new study which shows that the longer people are exposed to air pollution the worse their immune system performs. 

While the body’s natural ability to fight infections and other conditions does diminish over time, decades spent living with ambient air pollution are also now believed to be taking their toll. Inhaled particulate matter from emissions accumulate on the immune cells in lymph nodes linked to the lungs, which eventually reduce their ability to function. 

First published in the journal Nature Medicine, this is the first time strong evidence has been provided that this is a reason why respiratory disease risk increases with age, even in those that do not and have never smoked. Although that theory seems logical, the results were unexpected as scientists were not intentionally looking at air pollution influence on immunity. Instead, the focus was studying immune cells in multiple mucosal and lymphoid tissues after they had been taken from organ donors after death. You can read the full study here. 

‘When we looked at people’s lymph nodes, we were struck by how many of the nodes in the lung appeared black in color, while those in the GI tract and other areas of the body were the typical beige color,’ said Donna Farber, PhD, the George H. Humphreys II Professor of Surgical Sciences (in Surgery) and professor of microbiology & immunology at Columbia University Vagelos College of Physicians and Surgeons, who led the study.

‘When we imaged the lung’s blackened lymph nodes and found they were clogged with particles from airborne pollutants, we started to think about their impact on the lung’s ability to fight infection as people age,’ she continued. Tissues for 84 deceased individuals aged between 11 and 93 were involved in the study, none were smokers. 

In the UK, a pilot NHS scheme which allows doctors to prescribe heat to those at risk of respiratory illness, effectively paying their energy bills, has been expanded.

Image: Nani Chavez